Instructions

_output

●° rollup this-inside-out.js | node --expose-gc
Running 10 trials at 1000 records each:

Generated 1000 records
Growth: 2.74%

Generated 1000 records
Growth: -8.73%

Generated 1000 records
Growth: -0.08%

Generated 1000 records
Growth: 0.24%

Generated 1000 records
Growth: 0.07%

Generated 1000 records
Growth: 0.06%

Generated 1000 records
Growth: 0.07%

Generated 1000 records
Growth: 0.07%

Generated 1000 records
Growth: 0.07%

Generated 1000 records
Growth: 0.07%

Average memory growth for all 10 samples: -0.54%

main.js

import User, { create } from './user'

var size  = 10
var depth = 1000
var total = 0

console.log('Running %s trials at %s records each:\n', size, depth)

function test (depth) {
  var context = {}

  while (depth--) {
    create(context, { first_name : 'Sally', last_name  : 'Smith' })
  }

  console.log('Generated %s records', User.size(context))
}

for (var i = 0; i < size; i++) {
  global.gc()
  var memoryBefore = process.memoryUsage().heapUsed

  test(depth)

  global.gc()
  var memoryAfter = process.memoryUsage().heapUsed

  var growth = ((memoryAfter - memoryBefore) / memoryBefore) * 100

  console.log('Growth: %s%\n', growth.toFixed(2))

  total += growth
}

console.log("Average memory growth for all %s samples: %s%", size, (total / size).toFixed(2))

user.js

const DB = new WeakMap()

export function create (context, record) {
  var next = new Set(DB.get(context))

  next.add(record)

  DB.set(context, next)

  return record
}

export default {

  size(context) {
    return DB.has(context) ? DB.get(context).size : 0
  }

}